Prismatic glass reflector.



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PBISMATIO GLASS REFLBQTOR.

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OTIS ANGELO MYGATT, 0F PARIS, FRANCE;

PRISMATIC GLASS BEFLECTOR.

Specification of Letters Patent.

Application filed February 27. 1911. Serial No. 611,195.

Be it known that I, Oris ANeiELo MYGATLT,

a citizen of the United States, residing at Paris, France, have inventeda new and useful Improvement in Prismatic Glass Reflectors, ofwhich thefollowing is a specification.

The object of my invention is to produce a new and improved prismaticglass reflector combining efficient reflecting power with a mechanicalaction upon light rays which gives to its surface a varied and sparklingappearance, as well as having the advantage that the prisms inthemselves are more attractive in appearance.

A- transparent glass reflector having exterior radial reflecting prismsis well known in the art. Such articles,- however, .have had thedisadvantage of too uniform and monotonous an appearance, both inthemselvesv andin the effect of their illuminated surface. My newconstruction lends itself more readily to decorative treatment and alsoacts upon light rays so as'to produce alternating areas ofv d'erentlyilluminated surfaces, while at the same time furnishing a highlyefficient reflector. Y

The prisms on my reflector are substantially radial in direction. Thenovelty consists in making them with basesl of conlstantly varying widthso that the bounding lines of each individual prism alternately convergeand diverge. The height of the prism varies proportionately, keeping theapex angle at -the desired angle to produce total double reflection.Numerous experiments with transparent glass reflectors provided withexterior radial prisms of various types and photometric tests of theirrelative reflecting efficiency show that this construction does notdetract from the efliciency of the reector.

Figure 1 is a perspective of a preferred form of my invention; Fig. 2 isatop plan view of a prism; Fig. 3 is a vertical section of a prism.

In Fig. 1, A is a reflector of transparent glassformed by pressing in amold with the integral radial reflecting prisms B, B1, B2, etc., on itsouter surface. The bases of these prisms alternately narrow and widenwhile their height increases and decreases proportionately so that theapex angle remains that most favorable for producing total l'doublereflection. The angle of total or double reflection is intheneighborhood of 90. -In the reflector here exemplified, the adjacentprisms B and B1 are so constructed that at the point where one isnarrowest the other is widest, the advanta e of this construction ybeingthat the re ecting prisms thus cover the entire outer surface of thearticle.

Fig. 2 is a top plan View of prism B in Fig. 1, indicating bycross-hatching at points C and D the smallest and largestcross-sections. The variations'in the width of the glass bodythroughvwhich light rays pass to the reflecting surface operate to causethe amount of light transmitted per unit of area to varydisproportionately and give to the outer surface a shimmeringappearance. Similarly the varying area of the reflecting surface andtheir disproportionately varying efficiencies give to the inner surfacewhen the reflector is in use over an artificial light source, a wavedand variegated appearance ,and marked contrast to the dead uniformity ofsuch articles as heretofore manufactured. Fig. 3 is a vertical sectionthrough the apex line of t-he prism shown in Fig. 2. E is Patented Mal'.31, 1914:.-

a glass body of the reflector; F the reflecting prism. The apex linerises and falls, reaching its greatest height at points Gr where the.base of the prism is -widest and being lowest at points H where thebase is narrowest.

The waved construction shown in Fig. 1 provides a reflector whose entireouter surface is covered with reflecting prisms. Vith the curvedboundary lines the more gradual blendings of the different illuminatedareas gives the glass a changing and animated appearance. An incidentaladvantagebf the new form of prism employed in my invention is that theprisms themselves may be made in highly decorative forms and can bearranged with respect to each other so as to produce a great variety ofdecorative patterns.

I claim:

1. A reflector for artificial lights having upon the surface'thereof anumber of integral double reflecting prisms, the base and altitude ofeach of which changes a plurality of times throughout the length of theprism without substantially affecting its double reflect-ing property.

- 2. A reflector for artificial lights. having its surface substantiallycovered with in- In testimony Whereof,1 aiixiny signaturev tegralradially extendfing prisms, the base in the presence of two witnesses.

and altitude of each o said prisms varying p l repeatedly throughout thelength of the y, .OTIVS ANGELO MYGATT prism but preserving such a ratioto each y Witnesses:

other as to remain double reflecting through- Y E. LEAVENWORTH ELLIOTT,

out the length of the said prism. JOEL B. LIBERMAN.

Copies of .this patent may be obtained for ve cents eaoh, by addressingthe Commissioner of Patents;

' Washington, ID. C.

